textproduct: Rapid City

KEY MESSAGES

-Scattered showers and storms this afternoon and evening, shifting southeast overnight

-Seasonal and mainly dry the rest of the week

DISCUSSION

(This Afternoon Through Sunday) Issued at 1015 AM MDT Mon Sep 28 2026

Deep moisture will shift east today via a northern stream shortwave and associated sfc trough. This will transition the region into WNW flow aloft and allow for occasional cool fronts later in the week. Another monsoon wave will push NE into the region this afternoon and interact with a sfc trough dropping into the region. This will force showers and storms across the FA with the best chances across NW SD late this afternoon and scentral SD overnight. A few stronger storms are possible this afternoon across NW SD where increased flow aloft may allow storms to organize for a bit, supporting gusty winds and small hail. Things will dry out NW-SE into Tue, with lingering shower chances reaming across far eastern scentral SD through Tue morning. Seasonal and dry Tue and Wed. Cool fronts will knock down temps Thur, and again this weekend, with highs in the 60s behind these systems. Some light rain may develop with the NW flow impulses if enough forcing and moisture is realized, but these systems will be mainly dry.

AVIATION

(For the 18Z TAFS Through 18Z Tuesday) Issued At 1115 AM MDT Mon Sep 28 2026

Lingering MVFR/IFR conditions with low clouds from KECS to KCUT, although improvement to VFR is expected after 18-20z. Showers and thunderstorms possible throughout the afternoon, mainly across western SD and portions of northeastern WY (should stay south of KGCC), some of which may be strong to severe with large hail and damaging winds the main threats. Transient MVFR/IFR conditions possible in any stronger precipitation cores, however, VFR conditions will generally prevail. IFR/LIFR ceilings expected after29/09z across south-central SD through central SD (including KICR and possible KD07).

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.